1 /* addext.c -- add an extension to a file name
2 Copyright (C) 1990, 1997, 1998, 1999 Free Software Foundation, Inc.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; see the file COPYING.
16 If not, write to the Free Software Foundation,
17 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18
19 /* Written by David MacKenzie <djm@gnu.ai.mit.edu> and Paul Eggert */
20
21 #if HAVE_CONFIG_H
22 # include <config.h>
23 #endif
24
25 #ifndef HAVE_DOS_FILE_NAMES
26 # define HAVE_DOS_FILE_NAMES 0
27 #endif
28 #ifndef HAVE_LONG_FILE_NAMES
29 # define HAVE_LONG_FILE_NAMES 0
30 #endif
31
32 #include <backupfile.h>
33
34 #if HAVE_LIMITS_H
35 # include <limits.h>
36 #endif
37 #ifndef _POSIX_NAME_MAX
38 # define _POSIX_NAME_MAX 14
39 #endif
40
41 #include <sys/types.h>
42 #if HAVE_STRING_H
43 # include <string.h>
44 #else
45 # include <strings.h>
46 #endif
47
48 #if HAVE_UNISTD_H
49 # include <unistd.h>
50 #endif
51
52 char *base_name PARAMS ((char const *));
53
54 /* Append to FILENAME the extension EXT, unless the result would be too long,
55 in which case just append the character E. */
56
57 void
addext(char * filename,char const * ext,int e)58 addext (char *filename, char const *ext, int e)
59 {
60 char *s = base_name (filename);
61 size_t slen = strlen (s), extlen = strlen (ext);
62 long slen_max = -1;
63
64 #if HAVE_PATHCONF && defined _PC_NAME_MAX
65 if (slen + extlen <= _POSIX_NAME_MAX && ! HAVE_DOS_FILE_NAMES)
66 /* The file name is so short there's no need to call pathconf. */
67 slen_max = _POSIX_NAME_MAX;
68 else if (s == filename)
69 slen_max = pathconf (".", _PC_NAME_MAX);
70 else
71 {
72 char c = *s;
73 *s = 0;
74 slen_max = pathconf (filename, _PC_NAME_MAX);
75 *s = c;
76 }
77 #endif
78 if (slen_max < 0)
79 slen_max = HAVE_LONG_FILE_NAMES ? 255 : 14;
80
81 if (HAVE_DOS_FILE_NAMES && slen_max <= 12)
82 {
83 /* Live within DOS's 8.3 limit. */
84 char *dot = strchr (s, '.');
85 if (dot)
86 {
87 slen -= dot + 1 - s;
88 s = dot + 1;
89 slen_max = 3;
90 }
91 else
92 slen_max = 8;
93 extlen = 9; /* Don't use EXT. */
94 }
95
96 if (slen + extlen <= slen_max)
97 strcpy (s + slen, ext);
98 else
99 {
100 if (slen_max <= slen)
101 slen = slen_max - 1;
102 s[slen] = e;
103 s[slen + 1] = 0;
104 }
105 }
106